Background/significance:

Sorafenib, an oral targeted therapy, is currently being investigated as a potential adjuvant treatment in RCC in an international, phase III, double-blind, placebo-controlled trial (‘SORCE’). However, the trade-offs between the benefits and harms of this novel treatment are unknown. 

Objectives:

We determined the survival benefits judged necessary to make the harms of adjuvant sorafenib worthwhile for patients with resected RCC, and their doctors (urologists & medical oncologists).

Methods:

A sub-study determining patients’ and doctors’ preferences for adjuvant sorafenib was conducted as part of SORCE in Australia, New Zealand and the United Kingdom. Preferences were elicited by a self-administered questionnaire which used the time trade-off method to determine the minimum survival benefits judged sufficient to make adjuvant sorafneib worthwhile in 6 hypothetical scenarios. Baseline survival times were 5 and 15 years and baseline survival rates (at 5 years) were 50% and 65%.  4 scenarios compared 1 year of sorafenib with no adjuvant treatment and 2 scenarios compared 3 years of sorafenib to 1 year of sorafenib. All tests were 2-sided and non-parametric. Baseline responses of 180 patients (before sorafenib or placebo) and 96 of their doctors are reported.

Results:

Most patients had a technical college or university education (59%), worked full-time (62%), were married (80%), whilst fewer had dependent children (37%).  Patients’ sex, age and disease and treatment characteristics were not available for this analysis. The median benefit judged sufficient by patients to make 1 year of sorafenib worthwhile was 9 months beyond 5 years, 1 year beyond 15 years, 5% beyond 65%, and 3% beyond 85%; and, for 3 years of sorafenib was 1 year beyond both 5 years and 15 years . Preferences varied across the entire possible range from an extra 1 month to 15 years and an extra 1% to 35%. Patients’ preferences were not strongly associated with their demographics or expectations about quality of life during treatment.  The median benefit judged sufficient by doctors was 9 months beyond 5 years and 1 year beyond 15 years and 5% beyond 65% and 85%. Compared to patients, doctors’ judged larger benefits necessary for baseline prognoses of 15 years, 65% and 85% (p<0.04 for all). 

Conclusion:

Most patients judged small to moderate survival benefits sufficient to make adjuvant sorafenib for RCC worthwhile, whilst their doctors generally judged larger benefits necessary. Preferences varied over a wide range and had no consistent predictors. These results highlight the need to elicit patients’ attitudes, views and preferences for adjuvant sorafenib during the decision-making process.